Low temperature synthesis of nano-crystalline CaCu₃Ti₄O₁₂ through a fuel mediated auto-combustion pathway

Abstract

A novel, cost effective, environment-friendly and energetically beneficial alternative method for the synthesis of giant dielectric pseudo-perovskite material CaCu₃Ti₄O₁₂ (CCTO) is presented. The method involved auto-combustion of an aqueous precursor solution in oxygen atmosphere with the help of external fuels and is capable of producing high amount of CCTO at ultra-low temperature, in the combustion residue itself. The amount of phase generated was observed to be highly dependent on the combustion process i.e. on the nature and amount of external-fuels added for combustion. Two successful fuel combinations capable of producing reasonably higher amount of the desired compound were investigated. On a structural characterization grain size was observed to decrease drastically to nano-dimension compared to submicron-size that was obtained in a traditional sol-gel combustion and subsequent cacination method. Therefore, the method reported can produce nano-crystalline CaCu₃Ti₄O₁₂ ceramic matrix at an ultra-low temperature and is expected to be applicable for other multifunctional perovskite oxide materials.